I'd have to agree that there's not a big sense of urgency here - and that the suspense of the 'whats real and what isn't' thing is diminished by the fact that WE know even though Sam doesn't. But like you, I am curious to see where they're going with it.

I was a bit baffled about the God thing but now that I've had some explanation and theories thrown my way, its making a lot more sense. I'd like to think that somehow Castiel is still there and that maybe the door could be left open for him to come back.

As for the music, I didn't like the opening because I didn't feel like that song fit with the boys or the story at all - but I think we just get Carry On My Wayward Son for finales, not premieres. I'd be surprised if they changed that - kind of a nostalgia thing at this point. =)